Field of the Invention
The present invention relates to a reinforcement sleeve, and more particularly to a reinforcement sleeve that reinforces a portion in which optical fibers are connected to each other by fusion splice.
Description of the Related Art
A housing that receives therein a connection structure or a branch structure for optical fibers, what is called a closure or a fiber distribution frame, may be used to interconnect optical fibers of optical fiber cables or branch an optical fiber of an optical fiber cable. Within such a housing, optical fibers are connected to each other by fusion splice. In order to protect such a fusion splice portion of optical fibers, the fusion splice portion is covered with a resin tube (reinforcement sleeve) (see, e.g., JP 5607590 B). Such a reinforcement sleeve is received and held within a sleeve reception portion provided in the housing.
Some standards have been defined for such reinforcement sleeves. Sleeve reception portions that hold a reinforcement sleeve have also been designed to conform to the standards of reinforcement sleeves. The number of optical fibers contained in one optical fiber cable tends to increase due to an increased optical communication capacity in these days. Since the dimension of reinforcement sleeves and sleeve reception portions is designed in accordance with the aforementioned standards, it is difficult to change the number of optical fibers held in one sleeve reception portion within an existing housing. Thus, there are limitations to increasing the number of optical fibers that can be held in an existing housing.